1. Field of the Invention
The present invention relates to a device for monitoring the closure of the opening points of a motor vehicle. It is intended for monitoring the state of closure of the locks of doors, the trunk and other protected-access devices, such as the petrol flap, glove box, etc.
2. Description of the Related Art
At the present time, a closure contact is associated with each of the opening points to be monitored, and when this opening point is open or improperly closed this closure contact is actuated and sends a signal to a central unit which is arranged on the dashboard and which comprises visual-alarm devices, each associated with an opening point, in such a way that, when ignition contact is made, the driver is warned that, for example, a door is improperly closed.
This monitoring device requires a line for each opening point monitored, in order to send the above-mentioned signal to the central unit; the result of this is that the latter receives a line for each opening point monitored; this line can be bifilar or can comprise only a single wire if the return is made via earth. At all events, the monitoring of the state of closure of the opening points requires the wiring of a line between each of the accesses and the central unit which can therefore receive, for example, five or six conductors, each corresponding to an opening point.
Now the operations for the electrical wiring of a motor vehicle are difficult and continue to be expensive.
The object of the invention is, therefore, to provide a device for monitoring the closure of the opening points of a motor vehicle which makes it possible to reduce the number of conductors necessary for the connection between the opening points and the central monitoring unit and also to reduce the total length of the conductors used.